Process of manufacturing insulators



PIERRE JOSEPH HENRI BERNARD, OF MONTREAL, QUEBEC, CANADA.

PROCESS 01? MANUFACTURING INS'ULA'IORS.

Application led December 27, 1919.

To all whom z't may concern.'

Be 1t known that l, PIERRE Jessen l'lsNni' 'l BERNARD, a subject of theKing of lGreat Britain, residing at Montreal, -rovince of Quebec,Canada, have invented certain new and useful Improvements in Processesof Manufacturing Insulators; and l do hereby declare that the followingis a full, clear, and exact description of the invention, such as willenable `others skilled in the art to which it appertains to make and usethe same.

The present invention has relation to a process of manufacturinginsulators for electric heaters, and the principal object is to providea device of the character set forth, that is capable of relatively7great resistance, whereby a maximum degree of heat generation andsubsequent radiation is assured.

A further object of the invention is to isolate the insulated sheetsbetween convolutions of asbestos whereby the core tube is protectedagainst the heat generated by the resistance element wound thereon.

Another object of the invention is to provide novel means for securingthe insulating material upon the core tube.

lith the above and other objects in view which will hereinafter appearas the description continues, the invention consists of the novelfeatures of construction, combination and formation of parts as will behereinafter more fully described and particularly pointed out in theappended claim.

In the accompanying drawings has been shown a simple and preferred formof the invention, it being, howeverf understood that no limitationisnecessarily made to the precise structural details herein exhibited,but the right is herebyreserved to any changes, alterations -ormodifications to which recourse may be had that come within the scope ofthe claim without departing from the spirit of the invention orsacrifieing the eificiency of the same.

In the drawings:

Figure 1 is a detail sectional view of the improved heater;

Fig. 2 is a perspective view of the core tube and mica and asbestossheets, prior to the winding .of the latter upon the tube;

Specification of Letters Patent.

Patented May 18, 1920.

serial No. 347,757.

the heater illustrating the application of the resistance elementthereto; and,

Fig. is a sectional elevation of one end of the heater.

1n the embodiment of the invention illus-I trated in the drawings, thenumeral 10 designates a hollow metallic tube having its end portionsthreaded as at 11 and 12, while end portion 12 is reduced as at 13 andsuch reduced portions 13 is threaded as at 14.

Several sheets of mica 15 are assembled upon an outer sheet of asbestos16 and the tube 10 is placed thereupon. Thenthe mica and. asbestossheets 15 and 1G are wrapped around tube 10 which forms the cylinder 17.

Rings 1S and 19 and nuts 20 and 21 are screwed on the threaded endportions 11 and 12 of tube 10 and a plug 22 is screwed on the tubeextensions '13. The plug` 22 is exteriorly screw threaded as at 23 andcarries a pair of oppositely disposed terminal posts 24. and 25 to whichthe lead wires may be attached in the usual manner.

rEhe resistance element comprises relatively tine nichrome wire 26 whichis wound in spaced relation upon the insulation cylinder 17.

Proper contact connections are made with the terminal posts 24 and 25 atone end of the cylinder, which at the opposite end of the wire 26 is inconnect-ion with tube 10 by means of a tap screw 27, which latter takesinto the bore 28 thereof.

1 herve found that by the use of mica in sheets and the saine envelopedby asbestos in the manner stated, the insulated ycylinder 17 willconsist of alternate layers of mica and asbestos.

The tube 10 is completely insulated from the resistance element 26 andthe successive laminations' of asbestos and mica is immune from thegreat heat generated thereby.

Having thus fully described -my invention, what I claim as new anddesire to secure by Letters Patent is The method of manufacturinginsulatinc' cvlinders which com'rises wra Dino" s Pl s the center tubein sheets of mica and asbestos in such manner that each layer of micawill be inclosed by a layer of asbestos.

in witness whereof have hereunto set my hand.

HEERE JSEPH HENRI BERNARD.

